<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            width: 200px;
            height: 200px;
            background-color: pink;
        }

        /* div::before权重是2 */
        div::before {
            /* content是必须要写的 */
            /* display: inline-block; */
            content: '我';
        }

        div::after {
            content: '人';
        }
    </style>
</head>

<body>
    <div>
        是
    </div>
</body>

</html>